Andy Minuth

Premium+
  • Posts

    148
  • Joined

  • Last visited

Everything posted by Andy Minuth

  1. FYI: I wrote an article about that topic here on Lowepost.
  2. I am a bit disappointed that they set the 'Legacy' setting as the default in the new version. Which is the wrong setting.
  3. Welcome Kristopher, the scenes look nice. Two comments: Coming back to the same shots, was a bit too repetitive for me. I think there is some potential too tighten it up. I suggest to put your name at the end. Usually people have to see something interesting, before they pay real attention. So if someone likes something in the reel, his attention will go up, and hopefully he remembers your name at the end.
  4. I think You have to get the 'LUT Translator' app for it. The template is a clean vector field. With the app any (non spatial) color operation that is applied to that image can be translated into a LUT.
  5. AFAIK there are color management tools in Clipster. But we are not using them. We are just passing through the images. For a feature for example we are rendering 12bit X'Y'Z' Tiff files for the DCDM and dpx/ProRes in Rec.709 from Baselight. Syncing with sound, subtitles and DCP encoding is then done with Clipster.
  6. I am not quite sure what you are driving at. But with the 'Colour-Space' operator you can convert the image to 'RLab' which is related to CIE L*a*b*. The channels will be mapped like this: R -> red-green compononent G -> luminance component B -> blue-yellow component I am using this space sometimes for special treatment. I recommend to convert back to your working space after your RLab operations.
  7. Welcome to the forums Aljoscha. Here commercials are usually finished in Flame. (Sometimes Baselight) For features the image is finished in Baselight. DCDM and Rec709 images are rendered there, but the marriage of picture and sound is done with Clipster.
  8. The full name is 'Recommendation ITU-R BT.709 - Parameter values for the HDTV standards for production and international programme exchange' Recommendation: The ITU is responsible for defining worldwide standards. They are then published as recommendations. ITU-R: International Telecommunication Union Radiocommunication Sector BT: This recommendation is part of the 'Broadcasting service (television)' series. 709: The number of this paper. Rec.709, BT.709, etc. are different abbreviations for the same thing. You can download the paper for free here: http://www.itu.int/rec/R-REC-BT.709-6-201506-I/en Fun fact: As far as I know, a transfer curve for displays (e.g. for mastering or color grading) was not defined in ITU-R BT.709. Everyone was using Sony CRTs back then, which made them the de facto standard. In ITU-R BT.1886 the eotf for displays was finally defined.
  9. I think by tone mapping he means the process of mapping a higher dynamic range to a lower display dynamic range. In the ACES system for example this is done in the RRT. So when he applies his creative LUTs he is not changing the color-space of the footage. He also explains this later in the text. Usually a print emulation LUT for example is converting from Cineon Log Printing Densities to DCI P3. His LUTs are comparable to LMTs in the ACES system. They are creative looks that can be applied in high dynamic range. Probably there are some luma changes in these LUTs. Many looks depend on selective luma changes, for example changing the brightness in relation to the saturation and the hue.
  10. Hey there, as I am not a native english speaker, I wondered if there is a colloquial term of creative people that describes the technical 'Gamma'? In German for example there are terms that literally translate to 'heaviness' ("Schwere") and 'airiness' ("Luftigkeit"). They roughly describe what we control with the gamma parameter in a video signal (brightness and contrast at the same time without blowing out the whites or blacks). I know that every client has their own vocabulary and there are different meanings of the same word. But can You give some examples of what non-technical people say to You, when they ask for a gamma adjustment? Best, Andy
  11. Great article, Utsi! Thanks for sharing Your knowledge.
  12. I second that. The colour pipeline and toolset of the Baselight Plugin is identical to the full systems. But a huge drawback is the missing timeline and all the workflow tools. It is nice to learn, but to do a full project under pressure might be a bit of pita.
  13. Welcome to the forum, Mark. This You can do with the layer Blend-Modes (e.g. Luminance, Color). You can also choose a different 'blend-source', for example the original image or another layer. See this tutorial for an introduction. About Your first question I am not quite sure. A classic edge-detection tool is not available, unfortunately. Probably You are able to do a matte like this with 'MatteTool' (Erode/Dilate, In Out Blur) and Layer Blend modes, I guess. But the standard sharpen tool in Baselight is extremely powerful, when You learn about all the parameters.
  14. Started working on a new Thriller 'The other side' yesterday. I found some nice toned down looks during my first tests. The film utilises non-linear storytelling a lot. I think I will experiment with different creative white-points for the scenes. 

    1. Nicolas Hanson

      Nicolas Hanson

      Great, I'm looking forward to see your work!

  15. You are right, Paul. But the formula/matrix based transforms are also more "boring" and less popular among colourists. In general I suggest to use whatever transform one likes to go from Log to a display space. But for the inverse I advise to choose a clean one, that is not based on film or includes gamut de-compression.
  16. Out of curiosity I put Your example into Baselight and converted it to a Log space. All the available transforms are free of artefacts. Here is one result. Additionally I noticed that in Your inverted picture a lot of noise gets pushed, which is not optimal I think.
  17. By 'Linear' I assume You mean a videoish space like Rec.709 / 1886. The problem is that there is no perfect conversion from a low dynamic range color space like Rec.709 to a high dynamic range space like Cineon-Log. Going the usual way from Log to Rec.709 some information is lost, especially in the very bright and dark and also highly saturated areas. When you try to invert this lossy process, usually artefacts appear. This is a LogC to Rec.1886 Curve that I plotted years ago (for Legal and Extended Range which is unimportant here). Pay attention to the flat parts of the curve in the shadows and highlights. When you invert a curve like this, these parts are very steep and these code values are getting stretched a lot. This means that a tiny difference in the original results in a big difference in the result. Here I put two luma waveform plots of different Video (Rec.1886) to Cineon-Log transforms. You can see that the first one is very smooth compared to the other one. The first one is practically free of artefacts, while the second one has some problems. This is just for the luma part of the transform, additional problems occur for the colours (but this is more difficult to visualise). Filmlight optimised and smoothed the inverse transforms that are used by Truelight Colour Spaces within Baselight, to produce less artefacts. @Daniele Siragusano talks about it in this video around 06:20 - 06:50 After the explanation, my suggestions how to solve it: Generally I suggest to avoid a workflow like this (Video -> Log -> Video). But I know that usually the colourist cannot influence the camera settings Try to use a different transform, that produces less artefacts. I don't know if there are choices in Resolve. In Baselight the cleanest one is the inverse transform of the 'Truelight Video 1' DRT. Generally You can reduce the artefacts, when You avoid the extreme ends of the transform. This means it will probably work better if you reduce the contrast of the image, before you send it through the conversion. Once the picture is converted to Log without artefacts, You can increase the contrast as much as You want. If You have highly saturated colours in the picture, You can additionally try to reduce the saturation a bit before the conversion.
  18. Yes, I was not precise enough about terminology in my last post: Luminance should not be used in this context, because it is an absolute value that describes the amount of light in physics. The light emitted by a display for example is described by luminance and measured in cd/m2. Here the term relative luminance Y or luma Y' should be used. Relative luminance Y is a linear value and normalised to 1 or 100. Luma Y' is the same achromatic part of an image but nonlinear, it uses gamma compression. In video systems usually luma is used, but the formula is also true for linear components. Y = 0.2126 R + 0.7152 G + 0.0722 B Y' = 0.2126 R' + 0.7152 G' + 0.0722 B' Both formulas are valid. The ' indicates nonlinear values due to the gamma compression. These coefficients are intended for Rec.709 HD systems. For standard definition Rec.601 other coefficients are used: Y′ = 0.299 R′ + 0.587 G′ + 0.114 B′ These coefficients are also intended for JPEG images, which might explain the use in Photoshop. A quote about the term luminosity from Wikipedia: For further reading I recommend Charles Poynton and Wikipedia: http://www.poynton.com/PDFs/YUV_and_luminance_harmful.pdf http://www.poynton.com/notes/colour_and_gamma/GammaFAQ.html https://en.wikipedia.org/wiki/Luma_(video)
  19. Spatial resolution is mostly perceived via Luminance. In Rec 709 Luminance is calculated from RGB with this formula: Y' = 0.2126 R + 0.7152 G + 0.0722 B The Green channel contributes more than 70% to the Luminance signal.
  20. Contrast measurements are about the dynamic range of the projector. Sequential contrast is determined by comparing a completely black frame with the maximum brightness in another frame. It describes kind of the the maximum contrast of the device. Intra-frame contrast in comparison describes the maximum contrast within one frame, which is usually much lower. It is usually measured with a black/white checkerboard pattern or with a small white patch in a mainly black frame. Important to note is that the lower intra-frame performance of DCI compliant projectors is NOT due to an adaptive iris or dynamic light dimming (which mess up images in consumer displays). The reason lies mainly in the imperfection of the projection lens, which lifts the blacks because of flare. We know the effect from camera lenses: If there is a very bright object in the frame, the black level even of technically decent lenses like Master Primes is lifted a lot. To throw in some numbers, the DCI minimum specs and tolerances for example are: Sequential contrast: nominal 2000:1 review rooms (e.g. grading) 1500:1 theatres 1200:1 Intra-frame contrast: nominal 150:1 review rooms and theatres 100:1
  21. My guess is that the creators of the game did not pay enough regard for human color perception. I recommend to read a bit about MacAdam ellipses. An average human can not distinguish the color at the center of the ellipse from all colours inside it. In this picture the ellipses are 10x magnified in size, I overlayed the sRGB gamut, which is the one a computer display is usually working in. It is very obvious that colour differences in the green area are much more difficult to notice (ellipses are bigger). To explain the reasons for these perceptual differences, is beyond my knowledge.
  22. I am also interested in finding new podcast content. The Colorist Podcast that Nicolas mentioned is great. I listened to The Digital Cinema Cafe podcast. They touched color grading from time to time, but they stopped producing new episodes. Also 'The RC' by fxguide.com was interesting, but more focussed on digital cinematography. But got cancelled, too. What remains is the fxpodcast by fxguide.com. It is focussed on VFX but sometimes they are also touching color. There is one episode with Peter Doyle for example.